Prevalence of Inadequate Hydration Among US Children and Disparities by Gender and Race/Ethnicity: National Health and Nutrition Examination Survey, 2009-2012

We evaluated the hydration status of US children and adolescents. The sample included 4134 participants aged 6 to 19 years in the National Health and Nutrition Examination Survey from 2009 to 2012. We calculated mean urine osmolality and the proportion with inadequate hydration (urine osmolality > 800 mOsm/kg). We calculated multivariable regression models to estimate the associations between demographic factors, beverage intake, and hydration status. The prevalence of inadequate hydration was 54.5%. Significantly higher urine osmolality was observed among boys (+92.0 mOsm/kg; 95% confidence interval [CI] = 69.5, 114.6), non-Hispanic Blacks (+67.6 mOsm/kg; 95% CI = 31.5, 103.6), and younger children (+28.5 mOsm/kg; 95% CI = 8.1, 48.9) compared with girls, Whites, and older children, respectively. Boys (OR = 1.76; 95% CI = 1.49, 2.07) and non-Hispanic Blacks (odds ratio [OR] = 1.34; 95% CI = 1.04, 1.74) were also at significantly higher risk for inadequate hydration. An 8-fluid-ounce daily increase in water intake was associated with a significantly lower risk of inadequate hydration (OR = 0.96; 95% CI = 0.93, 0.98). Future research should explore drivers of gender and racial/ethnic disparities and solutions for improving hydration status.